On the panel assessing hearing impairment (6)
I believe the answer is:
injury
'impairment' is the definition.
(thesaurus)
'on the panel assessing hearing' is the wordplay.
'on' says to put letters next to each other.
'the panel' becomes 'jury' ('jury' can be a synonym of 'panel').
'assessing hearing' becomes 'in' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'jury' put after 'in' is 'INJURY'.
Can you help me to learn more?
(Other definitions for injury that I've seen before include "Wound" , "Physical hurt" , "Bodily damage" , "wrongful action" , "Female name" .)